This invention relates in general to automotive vehicles service and maintenance equipment therefor, and more particularly, to an adaptor for mounting wheel alignment instruments or other devices on the wheels of automotive vehicles.
A variety of equipment is currently marketed for ascertaining and adjusting the alignment of wheels on automotive vehicles, particularly the front wheels by which such vehicles are steered. This equipment includes instrumentation which must be mounted on the wheels themselves and to this end various wheel adaptors have been developed.
Perhaps the simplest and most common wheel adaptor grips the axially directed flange along the periphery of a stamped metal wheel rim at three locations so as to provide a three-point mounting. The actual gripping elements of these adaptors are nothing more than threaded studs made from a hardened steel. The studs lie along the rim flange, and the crests of the threads bite into the softer metal of the flange to firmly secure the adaptor in place. These adaptors possess the capability of urging the threaded studs outwardly away from the center of the wheel so that they bite into the inside face of the rim flange or urging the studs inwardly so that they will bite into the outside face of the rim flange. The reversibility is needed for some wheels have the inside face of the rim flange obscured, while others have the outside face obscured. Also, some wheels are castings of aluminum or magnesium, and most wheels of this type can only be gripped along their outside surfaces. Despite their convertibility, such adaptors are not easily transformed from an inside gripping capability to an outside gripping capability or vice-versa. Usually the adaptor must be disassembled to convert from one capability to the other. An adapter of this nature is disclosed in U.S. Pat. No. 2,475,502, issued July 5, 1949.